If you leave your bike outside, in the sun, in AZ, 2 years. Otherwise....
The British Rubber Manufacturers Association (BRMA) recommended practice, issued June, 2001, states, "BRMA members strongly recommend that unused tyres should not be put into service if they are over six years old and that all tyres should be replaced ten years from the date of their manufacture."
Several European vehicle manufacturers of high performance sports cars, coupes and sedans identify that "under no circumstances should tires older than 6 years be used" in their vehicle owner's manual.

How does he know bicycle tires use "inexpensive" elastomer compounds? Is that all bicycle tires or "inexpensive" bicycle tires?
What about lawn mower tires? Car tires? How about the tire on my wheel barrow? Those all look fine after 3 years. Does he replace all those too... just because?

That's the great thing about the internet - you can choose to believe what you want. I trust this chemist, and so does our business group. He and his team formulate the elastomers used in products that have sales approaching $500M annually.

I owe you a mea culpa on my first post - it was getting late and I wasn't careful with my wording. I used inexpensive to imply cheap and unsophisticated, when the tire formulation are anything but unsophisticated and use lower-cost materials driven by the nature and use of the end product.

He said tires and tubes don't particularly benefit from some of the additives he adds to the industrial formulations. And for most of the ones that would extend the rubber life we probably wouldn't be willing to pay for them. He estimated that the cost for one anti-oxidizing agent that the bicycle tires & tubes could benefit from the amount needed in a tire would cost more than the tire. Other anti-aging compounds would adversely affect wear, friction, or rolling resistance.

Is 3 years too conservative? Probably, but he's a conservative guy on these matters. He has said he would probable trust 3 year old tubes more than 3 year old tires, but I know I've pulled unused 3-year old tubes out of their box and had the presta valve fall off, the joint between the valve and the tube had dried out just sitting on the shelf. More than likely poor manufacturing, but time does tend to uncover those issues as well.

I tend to not worry about it as the tires and tubes in my bikes rarely last more than 3 years, either due to wear or damage.

I don't know about my co-worker, but I just replaced the tire on the Porsche because they were 4 years old even though they had less than 15,000 miles on them. They were noticeably less grippy and compliant than the new tires that went on.

you don't know what that term means or have never been around someone who suffers from it.

my bikes don't ******* squeak. that's the sign of someone who doesn't know his **** or maybe a deaf person.

Apologies for inadvertently poking some personal hornet's nest. I will avoid using psychological terms so loosely in the future. I was using the term not in the clinical sense, but in the informal way it is often used, to describe what the observer perceives as excessive meticulousness. Advising the OP to change his tubes to put his mind at ease, even after acknowledging that there is no functional reason for that, seemed to me (and still does) to be pointlessly over the top.

But different strokes for different folks. I withdraw anything that may have been perceived as criticism. You ride your way, and I'll ride mine.

Here's wishing you pleasant, quiet rides. I'm not deaf, but I do sometimes ignore the occasional squeak after satisfying myself that it doesn't indicate anything serious.

Peace out. :-)

We are far from pefect,
But perfect as we are
We are bruised, we are broken,
But we are goddamn works of art
Works of art

Advising the OP to change his tubes to put his mind at ease, even after acknowledging that there is no functional reason for that, seemed to me (and still does) to be pointlessly over the top.

i don't think i did that.

i only wrote that a rider should pursue what makes him more confident on the bicycle. confidence is most important to me. it allows me to bomb down a hill with traffic with a free mind.

concerning tubes, i use them until i no longer can. usually, the valves fail first. if tubes are old, patched, but still hold air, i put them on a bike that i will flip, and buy new tubes for my keeper.

tubes are relatively cheap, so no one should really get upset if someone feels the need to change them out every couple years. just take the old ones to you lbs, so they can be recycled.

Yossarian: don't worry. nothing's going to happen to you that won't happen to the rest of us.

found an email today from planetcyclery.com in my promotions gmail folder for $1.99 tubes (700x25c). it read, "this weekend only." i don't know the shipping cost. i usually buy 'em on ebay for under $6 shipped.

.

edit: bought 4 for $12.56 total, or $3.14/ea.

i made sure the valves are short ~ 33mm. i hate long stems.

Last edited by blackfrancois; 07-14-2017 at 11:45 AM.

Yossarian: don't worry. nothing's going to happen to you that won't happen to the rest of us.

2005? Has anyone here ever seen what happens to a rubber band after 12 years?

Not sure if that applies to butyl rubber. Possibly applies to latex tubes. Hint: Latex condoms have an expiration date.

Like others here, when my rear tire wears out, I put the front on the rear and put a brand new tire on the rear. When I take the tube out of that rear tire, the tube is pretty stuck to the inside of the tire to the point that I can't imagine I haven't done some damage getting it out.

“Statistics are like bikinis. What they reveal is suggestive, but what they conceal is vital.” -- Aaron Levenstein

"Beware of geeks bearing formulas." -- Warren Buffett

"Education is what you get when you read the fine print. Experience is what you get when you don't. -- Pete Seeger

I was contemplating this issue several days ago.
I was wondering whether I should throw out spare tubes once they get to a certain age.

Rubber deteriorates with time. But I know I have had tubes in an operating bike, with occasional use, for over 4 or 5 years.

I got to this point: since switching a perfectly good tube is an opportunity to introduce a problem, when is it worth it to switch, versus don't switch since that has its own likelihood of introducing error?

The one thing you know about a tube that holds air - for months at least - is that it sure holds air.

I got to this point: since switching a perfectly good tube is an opportunity to introduce a problem, when is it worth it to switch, versus don't switch since that has its own likelihood of introducing error?

The one thing you know about a tube that holds air - for months at least - is that it sure holds air.

Past performance is no guarantee of future returns.

“Statistics are like bikinis. What they reveal is suggestive, but what they conceal is vital.” -- Aaron Levenstein

"Beware of geeks bearing formulas." -- Warren Buffett

"Education is what you get when you read the fine print. Experience is what you get when you don't. -- Pete Seeger

I work with a PhD Chemist. His job is to formulate rubber-based elastomer compounds used on several of our products. He is also a serious cyclist. He changes his tires and tubes at least every 3 years. He said his experience with formulating rubber elastomers shows that the inexpensive elastomer compounds used on bicycle tires dry-out enough in 3 years due to typical environmental factors that they should be replaced.

He must not ride much if he doesn't wear out at least a rear tire in 3 years. I doubt he can cite a single study that might even suggest that a butyl rubber inner tube, mounted on a wheel, will deteriorate in any way in three years. Rubber doesn't "dry out," it oxidizes, and the amount of oxidation taking place inside the tire is miniscule. Your friend is either pulling your leg, trying to lord his expertise, or really doesn't understand what is going on. Ask him which it is.

He must not ride much if he doesn't wear out at least a rear tire in 3 years. I doubt he can cite a single study that might even suggest that a butyl rubber inner tube, mounted on a wheel, will deteriorate in any way in three years. Rubber doesn't "dry out," it oxidizes, and the amount of oxidation taking place inside the tire is miniscule. Your friend is either pulling your leg, trying to lord his expertise, or really doesn't understand what is going on. Ask him which it is.

You don't know the guy but by all means go ahead and attack him.

I know nothing I say will convince you that he actually knows what he's talking about - a half a billion dollars in sales rides on his work - so I'll just check check out of this discussion.
H

He must not ride much if he doesn't wear out at least a rear tire in 3 years. I doubt he can cite a single study that might even suggest that a butyl rubber inner tube, mounted on a wheel, will deteriorate in any way in three years. Rubber doesn't "dry out," it oxidizes, and the amount of oxidation taking place inside the tire is miniscule. Your friend is either pulling your leg, trying to lord his expertise, or really doesn't understand what is going on. Ask him which it is.

OK then. Now my question is, how long will a spare tube in its box last?

“Statistics are like bikinis. What they reveal is suggestive, but what they conceal is vital.” -- Aaron Levenstein

"Beware of geeks bearing formulas." -- Warren Buffett

"Education is what you get when you read the fine print. Experience is what you get when you don't. -- Pete Seeger

I know nothing I say will convince you that he actually knows what he's talking about - a half a billion dollars in sales rides on his work - so I'll just check check out of this discussion.

It's nice to know that "he actually knows what he's talking about." Did it ever occur to you that maybe some other people might know what they are talking about as well? Or would you say that this guy is the ONLY person who actually has any experience in rubber compounding, oxidative degradation, industrial chemistry, etc.?